The latest Wired features a list of contrarian environmental facts (organically raised cattle emit more methane gas than conventionally raised cattle, nuclear power is great, the Prius battery takes a lot of energy to make, etc.) but I was most surprised by this factoid:
Cooling a home in Arizona produces 93 percent few carbon dioxide emissions than warming a house in New England
The math is quite simple. Most people set their thermostat to somewhere between 68 and 76 degrees. When it's really hot outside (let's pretend it's August in Phoenix, which means 105 and humid) that means you need to cool the home by 35 degrees. But when it's really cold outside (and I just survived a long New England winter, which meant lots of 10 degree days) you need to heat the home by more than 60 degrees. As Wired notes, "a typical house heated by fuel oil emits 13,000 pounds of CO2 annually. Cooling a similar dwelling in Phoenix produces on 900 pounds of CO2 a year." The bad news, of course, is that you have to live in Phoenix.
This data point jives with that recent study showing that the citizens of Honolulu and Los Angeles emit the least amount of carbon dioxide per capita. At first glance, you might be surprised to learn that LA, the capital of car culture, is so atmospherically friendly. But a history of strict emission standards, coupled with urban density (LA county is the densest county in the country) and a temperate climate translates into a low CO2 footprint. As I noted in a Seed article from last year:
When most of us think about environmentally friendly places, we imagine rural landscapes and bucolic open spaces. We picture a terrain untouched by concrete. Cities, in contrast, seem like ecological nightmares. They are densities of pollution, artificial environments where nature consists of cockroaches, pigeons and florist shops.
But, according to Bettencourt and West, the conventional wisdom is exactly backwards. Cities are bastions of environmentalism. People who live in densely populated places lead environmentally friendly lives. They consume fewer resources per person and take up less space. (On average, city dwellers use about half as much electricity as people living outside the city limits.) The typical Manhattanite generates 30 percent less CO2 than the typical American.
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Not sure about your math on A/C. Most houses act a bit like a greenhouse, sunlight enters through the windows, and heats the roof to excruciatingly high temperatures. If a house used no heat or A/C its average temperature would be 10-20 degrees warmer than the average outside. That is probably made up for by the fact that A/C is a heat pump (like your refrigerator), and more than 1 unit of heat can be pumped at the expenditure of 1 unit of energy. Heat pumps are slowly coming into use for heating however.
Oil is hideously expensive right now, almost up to $5 a gallon. I have a 275 gallon tank.
When I moved in here it cost me $412.50 to fill the tank, at $5 it'll be $1,375.00. That's an increase of 333%, something I cannot abide.
So I didn't burn ANY oil last year. I used space heaters in the rooms that needed heat. And it was mild enough that the unheated parts stayed in the high 50's and low 60's.
Not sure about your math on A/C. Most houses act a bit like a greenhouse, sunlight enters through the windows, and heats the roof to excruciatingly high temperatures. If a house used no heat or A/C its average temperature would be 10-20 degrees warmer than the average outside. That is probably made up for by the fact that A/C is a heat pump (like your refrigerator), and more than 1 unit of heat can be pumped at the expenditure of 1 unit of energy. Heat pumps are slowly coming into use for heating however.
Some key points:
1) A/C is, as noted above, a heat pump. An A/C unit with a SEER of 10 produces 10 units of cooling per unit of energy. A heater produces 1 unit of heat per unit of energy. In theory, you might be able to create a reverse A/C unit (pump heat from the outside into the inside), though I suspect it would have problems with ice buildup.
2) A/C uses electrical power; while both hydrocarbon fuel and electricity have losses in distribution, energy loss in production is higher for electricity, so overall electrical power from hydrocarbon plants produces considerably more CO2 than the same power output from a furnace.
It's mostly (1) that makes A/C more efficient.
Can you provide a reference for LA being the densest county in the country? I've stood at Griffith Observatory and observed the entire LA basin stretched out before me. Most of the basin appears from that vantage point to be composed of buildings no taller than 2 or 3 stories. Relative to the entire basin (which is huge and concrete), the downtown high-rise areas are quite small.
it's in the actual brookings report. or see the ny times summary of the report:
"Population density and the availability of rail transportation were associated with lower per capita carbon emissions; the Los Angeles area is the most densely populated in the country, according to Brookings figures."
Do you know David Owen's "Green Manhattan" article, Jonah? I wasn't sure if the Seed article of yours that you quote was making reference to or drawing from his argument. His is in keeping with an "efficiency is the measure of environmental health" argument, with which I generally quibble (to put it mildly). Ben
Phoenix is humid?
This week's Economist backs you up on the density, no pun intended, of Los Angeles. "...Los Angeles sprawls less than it appears. It may be a low-rise city, but a surprising number of people pack into its "dingbat" houses and bungalows." (Dingbat? Anyone?) The Brookings carbon footprint numbers did not include local traffic and industry, also according to the Economist.
Additionally, possibly the biggest reason Phoenix fares well is that the electricity in the west is largely hydro. Which is why Lexington Kentucky came out worst, all coal, all the time. This region had all five of the worst, I believe. rb
I fail to see how strict emission standards translates into a lower CO2 footprint. The reverse is more likely, because the engine is detuned from top efficiency to lowest hydrocarbon emissions.bigTom: Heat pumps have been in use in the south for at least 25 years. The window air conditioners have a heat setting. A couple of solenoid valves switch the evaporator and condenser coil functions. Works the same as turning around the ac in the window.
You have to take into account that appliances and people in houses produce waste heat. This helps reduce the cost of warming and increases the cost of A/C. It is quite possible to build houses that need no heating except possibly a few extremely cold nights even in northern Sweden.
Anthony, heat pumps are not only possible but very popular in Sweden. The cheap solution is to suck the heat from the surrounding air, but the better although with a higher initial investment, is to drill a hole in the ground and use the heat stored in the ground. (or you could use a nearby lake)
In cities you can also use central heating/cooling where you pipe around hot/cold water. You often have waste heat that you can use, and if you are lucky enough to live along the coast the sea can provide a good source of cold water.
Compared to Atlanta or Miami Phoenix is not humid. Mid July to mid September is monsoon season and the humidity can get up to 30-40% and when it is 110 it gets really sticky. You don't have to live in Phoenix though, plenty of other places such as Yuma or Tucson have a similar climate but are not as large.
About higher CO2 emission in case of using electricity instead of oil - AFAIK near 20% electricity in USA produced at nuclear plants (almost zero carbon emission). Hydropower in Norway (above 90%), wind power in Spain and Denmark - you can produce carbon-free electricity, but can't burn oil without CO2 emission.